The Molecular Biology Core has been in operation for over four years. During this time, the objective of the Molecular Biology Core has been to provide to CFAR investigators the capacity to bridge the gap between cloning of a desired gene and the expression of a functional protein. Once the expression of the protein has been achieved, the Core has also provided the necessary services to scale up this procedures to obtain quantities sufficient for detailed biological and structural studies. In the last four years the Core has assisted over 25 CFAR investigators representing approximately 33% of the total number of CFAR investigators. The Core has established a repository of over 25 expression vectors and plasmids that are made available to CFAR investigators. The Core now has developed a repository consisting of seven recombinant HIV proteins such as Pr55gag, reverse transcriptase, and envelope. The essential services provided by the Molecular Biology Core have allowed UAB CFAR investigators to compete successfully for a variety of national awards including NCDDG, NCVDG, ACTG, as well as numerous R01s. The main objectives of the Core for the coming years remain the same: 1) To collect and maintain suitable plasmid vectors and hosts for expression of HIV and related recombinant proteins; 2) To provide a service for construction of recombinant plasmids for high level expression of HIV and related proteins; 3) To provide a service for purification of HIV and related proteins; 4) To establish an on-site repository for HIV plasmids with HIV genes/clones as well as recombinant HIV proteins; and 5) To train personnel to assist in the various phases of plasmid construction and expression and purification of recombinant proteins with the purpose of facilitating technology transfer. The overall success of the Core during the last four years has allowed this facility to function on a level nearly achieving the 50% chargeback rate, as put forth in the new guidelines for CFARs. It is clear then that with the availability of clone genes of some of the most interesting HIV proteins, often representing only minor components of a particular biological system, that the Core provides substantial advantages to UAB CFAR investigators wishing to express a recombinant protein for further detailed biological and structural studies described.